City authorities in St. Petersburg have ruled that plaques commemorating victims of Soviet persecutions are "inexpedient" and “illegal” and should be removed from the streets.

The City Committee for Development and Architecture announced its ruling in an official letter that was posted on December 6 on the Facebook account of Andrei Pivovarov, the chairman of the Open Russia civic movement.

The letter is addressed to an aide of lawmaker Vitaly Milonov, Aleksandr Mokhnatkin, who had questioned the legality of the plaques, calling them "illegal ads."

The committee wrote in its letter that it had instructed St. Petersburg's district authorities to consider the plaques illegal and to remove them.

Activists of the Last Address project, launched in 2014, place memorial plaques with names of the victims of the Great Purge launched by Soviet dictator Josef Stalin in the 1930s on the houses where they lived before their arrests.

About 800 such plaques have been placed in dozens of cities in Russia, Georgia, Ukraine, Moldova, and the Czech Republic.